29 research outputs found

    Slip Modeling and Estimation for a Planetary Exploration Rover: Experimental Results from Mt. Etna

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    For wheeled mobile systems, the wheel odometry is an important source of information about the current motion of the vehicle. It is used e.g. in the context of pose estimation and self-localization of planetary rovers, which is a crucial part of the success of planetary exploration missions. Depending on the wheel-soil interaction properties, wheel odometry measurements are subject to inherent errors such as wheel slippage. In this paper, a parameter-based approach for whole-body slip modeling and calibration is applied to a four-wheeled lightweight rover system. Details on the method for slip parameter calibration as well as the system-specific implementation are given. Experimental results from a test campaign on Mt. Etna are presented, showing significant improvements of the resulting wheel odometry measurements. The results are validated during a long range drive of approx. 900 m and discussed w. r. t. the advantages but also limitations of the method within a space exploration scenario

    Dual role of Mic10 in mitochondrial cristae organization and ATP synthase-linked metabolic adaptation and respiratory growth

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    Invaginations of the mitochondrial inner membrane, termed cristae, are hubs for oxidative phosphorylation. The mitochondrial contact site and cristae organizing system (MICOS) and the dimeric F(1)F(o)-ATP synthase play important roles in controlling cristae architecture. A fraction of the MICOS core subunit Mic10 is found in association with the ATP synthase, yet it is unknown whether this interaction is of relevance for mitochondrial or cellular functions. Here, we established conditions to selectively study the role of Mic10 at the ATP synthase. Mic10 variants impaired in MICOS functions stimulate ATP synthase oligomerization like wild-type Mic10 and promote efficient inner membrane energization, adaptation to non-fermentable carbon sources, and respiratory growth. Mic10's functions in respiratory growth largely depend on Mic10(ATPsynthase), not on Mic10(MICOS). We conclude that Mic10 plays a dual role as core subunit of MICOS and as partner of the F(1)F(o)-ATP synthase, serving distinct functions in cristae shaping and respiratory adaptation and growth

    A Robotic System for Solo Surgery in Flexible Ureterorenoscopy

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    Urolithiasis is a common disease with increasing prevalence across all ages. A common treatment option for smaller kidney stones is flexible ureterorenoscopy (fURS), where a flexible ureteroscope (FU) is used for stone removal and to inspect the renal collecting system. The handling of the flexible ureteroscope and end effectors (EEs), however, is challenging and requires two surgeons. In this article, we introduce a modular robotic system for endoscope manipulation, which enables solo surgery (SSU) and is adaptable to various hand-held FUs. Both the developed hardware components and the proposed workflow and its representation in software are described. We then present and discuss the results of an initial user study. Finally, we describe subsequent developmental steps towards more extensive testing by clinical staff

    Preliminary Results for the Multi-Robot, Multi-Partner, Multi-Mission, Planetary Exploration Analogue Campaign on Mount Etna

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    This paper was initially intended to report on the outcome of the twice postponed demonstration mission of the ARCHES project. Due to the global COVID pandemic, it has been postponed from 2020, then 2021, to 2022. Nevertheless, the development of our concepts and integration has progressed rapidly, and some of the preliminary results are worthwhile to share with the community to drive the dialog on robotics planetary exploration strategies. This paper includes an overview of the planned 4-week campaign, as well as the vision and relevance of the missiontowards the planned official space missions. Furthermore, the cooperative aspect of the robotic teams, the scientific motivation, the sub task achievements are summarised

    Finally! Insights into the ARCHES Lunar Planetary Exploration Analogue Campaign on Etna in summer 2022

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    This paper summarises the first outcomes of the space demonstration mission of the ARCHES project which could have been performed this year from 13 june until 10 july on Italy’s Mt. Etna in Sicily. After the second postponement related to COVID from the initially for 2020 planed campaign, we are now very happy to report, that the whole campaign with more than 65 participants for four weeks has been successfully conduced. In this short overview paper, we will refer to all other publication here on IAC22. This paper includes an overview of the performed 4-week campaign and the achieved mission goals and first results but also share our findings on the organisational and planning aspects

    Visual-inertial SLAM aided estimation of anchor poses and sensor error model Parameters of UWB Radio modules

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    Local positioning technologies based on ultra-wideband (UWB) ranging have become broadly available and accurate enough for various robotic applications. In an infrastructure setup with static anchor radio modules one common problem is to determine their global positions within the world coordinate frame. Furthermore, issues like the complex radio-frequency wave propagation properties make it difficult to design a consistent sensor error model which generalizes well across different anchor setups and environments. Combining radio based local positioning systems with a visual-inertial navigation system (VINS) can provide very accurate pose estimates for calibration of the radio based localization modules and at the same time alleviate the inherent drift in visual-inertial navigation. We propose an approach to utilize a visual-inertial SLAM system using fish-eye stereo cameras and an IMU to estimate the anchor 6D poses as well as the parameters of an UWB module sensor error model on a micro-aerial-vehicle (MAV). Fiducial markers on all anchor radio modules are used as artificial landmarks within the SLAM system to get accurate anchor module pose estimates

    Visual-inertial sensor fusion with a bio-inspired polarization compass for navigation of MAVs

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    We present the integration of a polarization compass in a visual-inertial sensor fusion framework onboard a Micro Aerial Vehicle (MAV). The polarization compass estimates the position of the sun indirectly from the pattern of skylight polarization even in cases where the sun is not visible. It is based on a polarization sensor which consists of a standard RGB camera and a small polarizing unit that creates three polarization images on the camera sensor. Due to its low weight and compact size it is ideally suited for small aerial systems. The readings from the polarization compass are fused with angular rate and acceleration measurements from an Inertial Measurement Unit (IMU) and the 6 Degrees of Freedom (DOF) pose changes from the Visual Odometry (VO) in an indirect extended Kalman filter (EKF). Two different approaches to integrate the readings from the polarization compass in the filter are presented and compared. We show in experiments that adding a compass to visual-inertial sensor fusion does not only eliminate the drift of yaw angle estimates but also improves overall state estimation of the system

    Optical-inertial tracking with active markers and changing visibility

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    This paper presents an optical-inertial tracking algorithm with explicit and assured optical marker identifica- tion. Active optical markers are sequentially or simultaneously triggered to achieve a maximum in quantity and quality of measurements available for tracking. Markers that appear in a camera image are identified by individual activation and are locally tracked in the 2D-images after initial identification. The 2D-position measurements of the cameras are combined with low latency measurements of acceleration and angular velocity from an inertial measurement unit. An Extended Kalman Filter is used for an ultra-tightly coupled data fusion, that takes advantage of all marker measurements with verified identity. The accurate, low latency tracking is robust with respect to temporary marker occlusions, as needed in applications where a robot is directly controlled with a tracked device. The tracking algorithms are implemented in real-time and verified with a test bed in a medical robotics context
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